The invention relates generally to devices for fastening objects, and more particularly to a fastener clip assembly for insertion into an engagement structure, such as a vehicle chassis, a hollow substrate, a wall, a plate, or any suitable surface.
A number of devices and fasteners are currently available for fastening panels, such as body panels and automobile interior trim piece panels, to the chassis of a vehicle. As used herein, a body panel refers to, for example, any interior or exterior body panel on a vehicle, a plastic interior trim piece, door panel, headliner or any interior trim piece. Additionally, the panel may be any suitable exterior body panel, such as a fender, bumper, quarter panel or door panel. The chassis of the vehicle may include any substrate, plate, body panel, structural framework, chassis component or subcomponent, wall or any suitable object.
These conventional fastener devices provide approximately relatively equal levels of insertion and extraction force. These body panels often attach to the chassis of an automobile with a relatively high level of insertion force while providing a relatively low level of extraction force.
Fastener clips, such as two piece fasteners (multi-piece), are known for attaching body panels to an automobile chassis. Two-piece fasteners are used so that if the panels are removed after original installation, such as to service the components in the door, they may be pulled apart so that one portion remains attached to the sheet metal while the other remains attached to the trim panel. The two pieces may also be reattached after separation. However, two piece fasteners require manufacturing of multiple pieces and labor intensive assembly of the two pieces and thus are relatively expensive.
One piece fasteners are typically less expensive than two or multi piece fasteners. One piece fasteners have a base to attach to a body panel and a post attached to the base and wings attached at least to the top of the post at a tip of the fastener for fastening to a frame slot. However, if the frame slot and the fastener are misaligned then the forces on the wings are unequal since the wing closest to the slot edge will experience higher wing compression while the other wing will have insufficient springing force to engage the slot. As the clip is forced into the slot, such high forces on one wing may cause the wing to break off thus rendering the fastener incapable of fastening the body panel to the frame. Worse, the broken, damaged or weakened wing can cause detachment of the body panel or contribute to rattles.
The wings of conventional fasteners have a sharp, unsmooth groove to engage the edge of the frame slot. When the clip is removed however, the sharp edges of the frame slot cut into the softer plastic and cut the groove. During manufacture, the slots are typically formed in the frame of the vehicle, such as in an inner roof or door sheet metal structure, by punching the sheet metal. As the punch enters the sheet metal, the outer part of the sheet metal is pushed toward the inside and a metal puncture or ridge is formed on the inside of the sheet metal. The resulting slot edge on the outer part of the slot is relatively smooth; however the inner part of the slot edge is sharp and rough. Upon removal of the fastener clip, the sharp edges of the frame cut off the groove so that the clip may not be reinserted and reusable.
If the slot is off-center or if the sheet metal varies in thickness or if tolerances in production of the slot in the vehicle chassis or in the trim-piece exist, for example, then engagement of one portion of the hole in the chassis with one of the wings may not provide suitable frictional engagement. Twisting of the body panel will be likely more prevalent because less than all contact points are actually made with the slot of the vehicle chassis. As a result, conventional single piece fasteners do not self-align themselves when the fastener and the body panel are misaligned, and are prone to wing breakage such that the fastener cannot be re-attached.
Conventional fasteners typically do not adequately secure the panel to the vehicle chassis having variations in slot size and location or sheet metal with different curvature or thicknesses throughout. Conventional single piece fasteners do not self-align themselves when the fastener and the body panel are misaligned, and are prone to wing breakage such that the fastener cannot be re-attached. Also, conventional fasteners are not suitable when subjected to a variety of environmental conditions, such as in the presence of vibration at various levels of amplitude and frequency. For example, conventional fasteners of this type typically do not prevent or minimize the amount of buzzing, rattling or any other type of noise that may cause attention to the occupants of the vehicle or otherwise weaken the attachment. Conventional fasteners do not adequately accommodate various levels of production tolerances, such as various dimensions amongst, for example, the body panels as well as the vehicle chassis. Thus, conventional fastener devices typically do not self-align nor adequately fasten to a range of sheet metal thicknesses and do not minimize or eliminate buzzing and rattling and do not sufficiently accommodate variations in production tolerances. As a result, wear, squeaks, rattles, buzzing, corrosion and loss of elasticity and loss of sealing may result, especially after years of vehicle operation and exposure to vibration, heat, humidity, and other environmental conditions.
While the invention is subject to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and the accompanying detailed description. It should be understood, however, that the drawings and detailed description are not intended to limit the invention to the particular embodiments. This disclosure is instead intended to cover all modifications, equivalents, and alternatives falling within the scope of the present invention as defined by the appended claims.